Polyether containing cycloaliphatic structural elements and hydroxyl groups

ABSTRACT

Process for preparing a composition of matter suitable for the production of molded articles or coatings said process comprising preparing a polyether by reacting an unsubstituted, halogensubstituted or alkyl substituted hexahydrophthalic acid diglycidyl ester with a cycloaliphatic diol in a molar ratio of 1:0.8 to 0.8:1, and mixing the resulting polyether with a polyisocyanate.

United States Patent Jellinek et al.

[ Jan. 21, 1975 POLYETHER CONTAINING CYQLOALIPHATIC STRUCTURAL ELEMENTS AND HYDROXYL GROUPS Inventors: Karl Jellinek, Letmathe; Post Udo,

Wissmar uber Giessen; Rudi Oellig, Duisburg-Meiderich, all of Germany Assignee: Rutgerswerke Aktiengesellschaft,

Frankfurt am Main, Germany Filed: Apr. 19, 1973 Appl. No.: 352,844

Related U.S. Application Data Division of Ser. No. 227,256, Feb. 17, 1972, Pat. No. 3,784,601.

Foreign Application Priority Data Feb. 17, 1971 Germany 210744] U.S. Cl 260/75 EP, 117/132, 260/37 N, 260/77.5 AP, 260/77.5 AN, 260/78.4 EP,

260/75 NK Int. Cl C08g 22/08 Field of Search 260/75 EP, 78.4 EP

[56] References Cited UNITED STATES PATENTS 7/1968 Hale et al 260/75 EP 11/1971 Siggel et al.... 260/75 EP Primary ExaminerM. 1. Welsh 4 Claims, N0 Drawings POLYETHER CONTAINING CYCLOALIPHATIC STRUCTURAL ELEMENTS AND I-IYDROXYL GROUPS This is a division of application Ser. No. 227,256, filed Feb. 17, 1972 now U.S. Pat. No. 3,784,601.

This invention relates to the use of polyethers, which carry hydroxyl groups and have a cycloaliphatic base structure, for the production ofmolded articles or coatmgs.

Aromatic polyethers containing hydroxyl groups are known in the art. They can be produced, for example, by condensation of bivalent phenols with diepoxy compounds in a molar ratio of about 1:1 with the aid of a catalyst. Solid products with variable molecular weights are obtained. The polyethers have a linear structure, and carry hydroxyl groups in the chain and at the ends of the chain.

In practice, the diglycidylether of bisphenol A and 4,4dihydroxydiphenyl methane have been found to be particularly suitable as the phenolic component of the condensation reaction. The resulting high molecular weight polyethers are particularly suitable as binders in varnishes and adhesive compositions. The polyethers are surprisingly resistant to chemical attack by acids, caustics, and organic solvents. Also, they exhibit a high degree of adhesion to almost all metallic, inorganic and organic substances. Thus, these aromatic polyethers have been found to be important components in the production of protective coatings for surfaces where corrosion resistance is important.

Aromatic polyethers are generally dissolved in suitable solvents. By cross-linking the polyethers with polyisocyanates, varnishes are obtained which can be used under hot or cold conditions.

The known polyethers prepared from aromatic polyphenols have not proven entirely satisfactory when exposed to ultraviolet light and weathering. Coatings prepared from these polyethers yellow after a short period of time outdoors. Furthermore, when fillers or pigments are added to these coatings, chalking becomes noticeable, which at first makes the surface film appear unattractive, then finally destroys it. The accumulation of aromatic structural elements existing in the binder is considered to be the reason for this behavior.

It now has been found that the disadvantages mentioned above can be substantially overcome without appreciably affecting the previously mentioned advantages associated with the use of the aromatic polyethers containing hydroxyl groups. This is accomplished by using polyethers, which consist largely of cycloaliphatic structural elements, and which contain certain selected hydroxyl groups.

Accordingly, this invention provides a process for preparing a composition of matter suitable for the production of molded articles or coatings said process comprising preparing a polyether by reacting an unsubstituted, halogen-substituted or alkyl substituted hexahydrophthalic acid diglycidyl ester with a cycloaliphatic diol in a molar ratio of 1:0.8 to 0.811, and mixing the resulting polyether with a polyisocyanate.

The polyethers employed in practicing this invention have the following general structural formula:

l on l on EXAMPLE 1 Solvent containing Varnish (Production of a Coating) a. Production of a Polyether Raw materials:

(1 mole) (1 mole) 286 g hexahydrophthalic acid diglycidyl ester 240 g 4,4'-dihydroxydicyelohexylpropane The hexahydrophthalic acid diglycidyl ester (1 mole) is heated to 100C in a flask, which is equipped with an agitator and thermometer, and the dihydroxdicyclohexylpropane is added in several increments. The resulting mixture is heated to 160C, and is reacted at this temperature until the presence of epoxy groups is no longer detectable. The resin prepared in this manner has the following characteristics:

Softening range Content of hydroxyl groups b. Composition and Production of a Two-Component Varnish Component A 52.9 g of the polyether described under a) is dissolved in cyclohexanone to obtain a solution having a 40% solids content.

2) 14.2 g titanium white RN 57 3) 7.1 g Blane fixe N 4) 7.1 g Microtalc AT extra M 18.7 g tris (isocyanatohexamethylene)-biuret Components l through (4) are dispersed in a ball mill to obtain a particle size below 10 a. After mixing components A and B in a weight ratio of 8l.3:18.7, a varnish is obtained having the following characteristics:

Pigment/Binder ratio 1 1.24 Fillers on a solids basis 44.7% Viscosity DIN 4/20 57.0 sec. PVK 20% This varnish when applied to a metal substrate with a brush or spray gun, will result in a film having the following characteristics:

c. Characteristics of the Varnish Film T I after 6 hours Drying time:

T 7 after 20 hours Thickness of the Film: 50 p. Pandelharte after 30 d RT: 145 sec. Erichsen depression 4 5 Stage Drop from 98 to 92% No change EXAMPLE 2 Solvent containing Varnish a. Raw materials:

286 g hexahydrophthalic acid diglycidyl ester 196 g tricyclodecanedimethylol (TCD alcohol) (I mole) (l mole) The resin is produced under the same conditions as stated in Example 1(a).

The resin prepared in this manner has the following characteristics:

Softening range Content of hydroxyl groups so 85C 6% b. Production and Characteristics of the Varnish 27.1 g of the polyether described under a.

. 19.2 g cyclohexanone/methylisobutyl ketone l:l

. 14.9 g titanium white RN 57 7.4 g Blanc fixe N 7.4 g microtalc AT extra 24.0 g tris-(isocyanatohexamethylene)-biuret Components 1. through 5. are dispersed in a ball mill to obtain a particle size below 10 t. After adding and mixing in component 6, a varnish with the following characteristics is obtained:

Pigment/Binder ratio: l l.52 Fillers on a solids basis 39.7% Pot Life 8 hours PVK: l5%

c. Characteristics of the Film of Varnish After application to a metal substance by means of a spray gun or by painting with a brush, a film having the following characteristics is obtained:

Reduction of gloss after 6-months storage in an industrial atmosphere (gloss meter according to Lange, measuring angle 45), Drop from 92 to 89% In order to make clear the difference between coating masses on cycloaliphatic base according to this invention and those on common aromatic base the results of the technical test for varnishes ofa system consisting of a bisphenol resin (phenoxy-resin) with a softening range from -l00, an epoxy equivalent from 900 1,000 and a hydroxy group portion of 6 per cent are given below. The recipe for the varnish is the same as written in Example 2.

Pot time: 7 h

Film thickness 50 p.

Drying time: T l after3 hours T 7 after 16 hours Pendelharte after 20 d RT: 95 seconds Erichsen depression: 6 7 mm Yellowing (Xeno test method) 500 hours Chalking resistance DlN 53 I59 (evaluation according to the chalking scale of the Titanium Company):

Reduction of gloss after-6-months storage in an industrial atmosphere (gloss meter according to Lange. measuring angle 45):

noticeable change Stage 8 Drop from 80 to 60% EXAMPLE 3 Coating Powder a. Production of a Polyether As described in Example 1 under a. b. Production of a Coating Powder Raw materials:

g of the polyether described under a) 85 g of an agent to form an adduct (an isocyanate was used as the agent, which was produced by reacting toluene diisocanate and 4,4'-dihydroxydiphenyl propane in a molar ratio quantity).

g titanium dioxide as filler The polyether is melted on a heated two-roll mill at a roll temperature of l00l l0C, and is mixed with the filler. After the filler has been well wetted and distributed homogeneously, the agent for the formation of the adduct is added, and this is mixed at the same temperature for 1-2 minutes. Subsequently the mixture is immediately cooled, and the mixture at first is preground in a disk attrition mill, it being further comminuted afterwards in an impeller breaker. A screened grain fraction of 3080 p.is sutiable for use as a coating powder and can be applied with the customary application device. The material is suitable both for operating with an electrostatic spray gun and in fluidized beds, as customary in whirl sintering. 0. Production of the Coating To harden the powder to be applied to metallic surfaces, a baking time of 30 minutes at l80C is employed. d. Characteristics of the Film Yellowing (Xeno test Method):

500 hours Chalking resistance DIN 53 I59 I year (evaluation: chalking scale of the Titanium Company):

No noticeable change atmosphere: No noticeable change Layer thickness: 80 p. Development: Good Erichsen depression: 8 10 mm Pendelharte according to Konig: l9O ZlO Yellowing (Xeno test method) Clearly visible Chalking resistance DIN 53 159 1 year (evaluation according to the chalking scale of the Titanium Company): 6 7

Reduction in gloss after 6-months storage in an industrial atmosphere: Clear change What is claimed is: l. A polyether of the formula:

in which R unsubstituted, halogensubstituted or alkyl substituted cyclohexylene ring,

R cyclohexylene, tricyclodecane-dimethylene or cyclohexanedimethylene, 4,4propancdicyclohexylene and n an integer from about 10 to about 40.

2. Polyether of claim 1 which is a reaction product of an unsubstituted, halogen-substituted or alkyl substituted hexahydrophthalic acid diglycidyl ester with :1 cycloaliphatic diol in a molar ratio of 1:08 to 0.811.

3. Polyether of claim 2 in which the ester is unsubstituted hexahydrophthalic acid diglycidyl ester.

4. Polyether of claim 3 in which the diol is selected from the group consisting of 4,4-dihydroxydicyclohcxylpropane and tricylodecanedimethylol. 

2. Polyether of claim 1 which is a reaction product of an unsubstituted, halogen-substituted or alkyl substituted hexahydrophthalic acid diglycidyl ester with a cycloaliphatic diol in a molar ratio of 1:0.8 to 0.8:1.
 3. Polyether of claim 2 in which the ester is unsubstituted hexahydrophthalic acid diglycidyl ester.
 4. Polyether of claim 3 in which the diol is selected from the group consisting of 4,4''-dihydroxydicyclohexylpropane and tricylodecanedimethylol. 